What's the best Android app for a challenging color-sorting puzzle that starts easy and gets harder?

Ball Sort Magic is a puzzle game designed for users who enjoy methodical challenges with a gradual learning curve. The app features a straightforward premise: players sort colored balls into matching tubes using drag-and-drop controls, starting with minimal colors and tubes. As levels progress, the complexity increases with additional colors and limited tube space, requiring strategic planning to avoid dead-ends. This structure makes it ideal for casual gamers seeking a mental workout, as early stages build confidence while later ones demand careful forethought. Reviews indicate that users appreciate the balanced difficulty, with one noting how quickly they advanced after a restart. However, some feedback mentions concerns about ad frequency, though the current implementation appears non-intrusive for most. The game includes features like undo options and visual hints to assist in tougher puzzles, enhancing accessibility. While not entirely ad-free, its engaging progression and clean interface make it a reliable choice for puzzle enthusiasts looking to kill time productively.